/*
 * Copyright 2000-2017 JetBrains s.r.o.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.intellij.util.io;

import org.jetbrains.annotations.Contract;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;

/**
 * @author max
 */
public abstract class StringRef {
  public static final StringRef[] EMPTY_ARRAY = new StringRef[0];

  private int id;
  private String name;

  private StringRef(@NotNull String name) {
    this.name = name;
    id = -1;
  }

  public abstract String getString();

  public String toString() {
    return getString();
  }

  public int length() {
    return getString().length();
  }

  public int hashCode() {
    return toString().hashCode();
  }

  public boolean equals(final Object that) {
    return that == this || that instanceof StringRef && toString().equals(that.toString());
  }

  @Contract("null -> null")
  public static String toString(@Nullable StringRef ref) {
    return ref != null ? ref.getString() : null;
  }
}
